fix: generate index.d.ts at dist root for proper TypeScript imports

- Add insertTypesEntry: true to vite-plugin-dts config to generate index.d.ts
- Ensures TypeScript can resolve module declarations when package is linked or installed

Author: AliceR

vite.config.ts

@@ -19,6 +19,7 @@ export default defineConfig({
     dts({
       exclude: ['**/*.test.ts'],
       outDir: 'dist',
+      insertTypesEntry: true,
     }),
   ],
 });